The Skeleton Ch. 7

206 bones in human body Skeleton is divided into: Axial skeleton (80) - Skull, Thoracic Cage, and Vertebral Column Appendicular skeleton (126) - Arms, Legs, Pectoral Girdle, and Pelvic Girdle

Shape: Long bones: limbs Short bones: carpals and tarsals - sesamoid short bone that forms in a tendon Flat bones: cranium, sternum and scapula - two layers of compact with spongy bone in between (diploe) Irregular bones: vertebrae

Bony landmarks: Depression: (blood vessels and nerves to pass) Fissure - narrow, slitlike opening Foramen - round or oval opening through the bone Fossa - shallow and may serve as an articular surface Sulcus/meatus/canal - canal-like passageway Sinus: cavity within a bone Groove - furrow

Processes: Bony prominences (muscle and ligament attachment) Tuberosity - large rounded projection; may be roughened. Crest - narrow ridge of bone Trochanter - very large, blunt, irregulary shaped process (femur) Line - narrow ridges of bone; less prominent than crest Tubercle - small rounded projection Epicondyle - raised area above a condyle Spine - sharp, slender, often pointed

Processes: form joints Head - bony expansion carried on a narrow neck Facet - smooth and nearly flat articular surface Condyle - rounded articular projection Ramus - armlike bar of a bone

Gross Anatomy of the human skeleton

Axial Skeleton

1. Skull    a. Cranial bones       1- frontal             (a) sinus             (b) supra-orbital ridge             (c) supra-orbital foramen         (d) coronal suture (between frontal and anterior border of parietals) (e) glabella

  2- parietal           (a) sagittal suture: b/w parietals        (b) lambdoid suture: b/w posterior parietals and occipital bone        (c) squamous suture: b/w parietals and squamous of temporal (d) diploe 3- occipital          (a) occipital condyles          (b) foramen magnum          (c) superior and inferior nuchal lines       (d) external occipital protuberance (EOP) (e) hypoglossal canal (XII: Hypoglossal) (f) pharyngeal tubercle (g) basion (h) opisthion (i) clivus (j) internal occipital protuberance (IOP)

4- temporal (a) external acoustic (auditory) 4- temporal         (a) external acoustic (auditory) meatus         (b) internal acoustic meatus (VIII: Vestibulocochlear)          (c) styloid process         (d) petrous portion         (e) jugular foramen (IX:Glossphrayngeal) (X: Vagus) (XI: Accessory)       (f) carotid canal                                     (g) foramen lacerum (h) zygomatic process (i) mastoid process (j) infratemporal fossa (k) mandibular fossa (l) stylomastoid foramen (CN VII: Facial)

  5- sphenoid        (a) greater and lesser wings        (b) pterygoid processes - medial - lateral (c) anterior clinoid process        (d) sella turcica - dorsum sellae - posterior clinoid process - hypophyseal fossa         (e) optic canal (CN II: Optic nerve)         (f) superior orbital fissure - CN III, IV, VI (g) foramen ovale (CN V: Trigeminal) (i) foramen spinosum (j) foramen rotundum (CN V: Trigeminal)

6- ethmoid             (a) perpendicular plate             (b) crista galli             (c) cribriform (horizontal) plate - CN I (olfactory)             (d) middle nasal concha b. Facial bones 1- nasal bones    2- lacrimal bones (a) lacrimal fossa    3- zygomatic bones             (a) orbital plate         (b) frontal process     (c) temporal process             (d) maxillary process

4- maxilla      (a) alveolar margin      (b) infra-orbital foramen      (c) palatine processes (d) incisive fossa (e) anterior nasal spine   5- palatine bones (a) greater palatine foramen (b) choanae (posterior nares)

6- mandible     (a) ramus     (b) condyle     (c) angle    (d) body     (e) coronoid process     (f) alveolar margin     (g) mental foramen (h) mandibular foramen (i) lingula

7- vomer 8- inferior nasal concha c. Paranasal sinuses        (1)  frontal        (2)  ethmoid        (3)  sphenoid        (4)  maxillary

2. hyoid bone  (a) greater horn (b) lesser horn                    

3. ribs (12 pairs) 1-7: true ribs 8-10: false ribs 11,12: floating ribs a. head b. neck c. tubercle d. body e. costal cartilage 4. sternum         a. manubrium         b. jugular notch         c. angle of Louis         d. body         e. xiphoid process         f. clavicular notch

Auditory ossicles          (a) Malleus (hammer)          (b) Incus (anvil)          (c) Stapes (stirrup)

vertebrae:      a. (7) cervical - atlas & axis(C1 & C2)          axis with dens (odontoid process) C3-C5      b. (12) thoracic: T1-T12      c. (5) lumbar: L1-L5       d. sacrum (5-fused)-Ala      e. coccyx (4-fused)

C1: atlas - anterior arch with tubercle - posterior arch with tubercle - lateral mass - transverse process - transverse foramen (vertebral artery)

C2: axis or epistropheus - odontoid or dens - transverse foramen - transverse ligament (atlas)

ADI interval Atlanto dens interval

Parts of a typical vertebrae: a- lamina b- pedicles c- centrum (body) d- spinous process e- superior and inferior articulating processes f- vertebral foramen g- intervertebral foramen h- transverse processes i- mamillary processes (lumbar) j- costal facets

Lumbar Spine

Sacrum: 5 fused         a. sacral canal      b. sacroiliac joint      c. sacral foramen      d. median sacral crest      e. sacral hiatus      f. sacral promontory      g. apex      h. ala Coccyx: 4 fused a. coccygeal cornu

Appendicular skeleton

B. APPENDICULAR SKELETON      Bones of the pectoral Girdle           1- scapula  (right or left)              a. coracoid process              b. acromion process              c. spine              d. supraspinous fossa              e. infraspinous fossa              f. glenoid fossa (cavity) g. supraglenoid tubercle              h. subscapular fossa              i. suprascapular notch              j. vertebral (medial) border              k. axillary (lateral) border              l. inferior angle

Shoulder dislocation (skateboard injury)

2- Clavicle a. acromial extremity b. sternal extremity c. conoid tubercle

Bones of upper extremity: arm and forearm 1- humerus (right or left) a    Bones of upper extremity: arm and forearm        1- humerus  (right or left)           a. head           b. neck: surgical and anatomical           c. greater and lesser tubercle            d. intertubercular groove           e. deltoid tuberosity           f. medial and lateral epicondyles           g. trochlea           h. capitulum           i. olecranon fossa           j. coronoid fossa k. radial fossa l. radial groove

2- radius (right or left) a. head          b. neck       c. shaft       d. styloid process       e. ulnar notch f. radial tuberosity g. area for lunate and scaphoid bone 3- ulna (right or left)       a. olecranon process       b. trochlear notch       c. radial notch       d. coronoid process       e. head        f. styloid process  g. area for triquetral bone

4- carpals (8) - Scaphoid - Lunate - Triquetral - Pisiform - Trapezium - Trapezoid - Capitate - Hamate        metacarpals (5)     phalanges (14)                 a. proximal                 b. middle (not on thumb)                 c. distal 

 Bones of the pelvic girdle (os coxae) 1- ilium       a. iliac crest       b. anterior superior and inferior iliac spine       c. posterior superior and inferior iliac spine       d. iliac fossa       e.  sacroiliac joint       f. greater sciatic notch

2. ischium a. ischial spine b. lesser sciatic notch c 2. ischium        a. ischial spine        b. lesser sciatic notch        c. ischial tuberosity d. ramus of ischium 3. pubis        a. pubic rami        b. pubic symphysis c. pectineal line d. pubic tubercle         I) acetabulum (acetabular fossa)     II) obturator foramen 

Bones of thigh and leg 4. femur (right or left) a. head b Bones of thigh and leg     4. femur  (right or left)          a. head          b. fovea capitis          c. neck          d. greater and lesser trochanter          e. gluteal tuberosity f. calcar          g. shaft          h. linea aspera          i. epicondyles          j. medial and lateral condyles          k. intercondylar fossa          l. patellar surface m. nutrient foramen

5.  tibia (right or left)       a. tibial condyles       b. intercondylar eminence       c. medial malleolus       d. shaft       e. tibial tuberosity f. Gerdy’s tubercle g. fibular notch 6. fibula       a. head       b. shaft       c. lateral malleolus 7. patella 

Bones of ankle and foot 8- tarsus (7) tarsal bones      a. calcaneus - sustentaculum tali - tuber calcanei b. talus c. cuboid d. navicular e. medial, intermediate and lateral cuneiforms 9. metatarsals (5 - tuberosity of 5th metatarsal 10. phalanges (14)            (1) proximal            (2) middle (for four toes)            (3) distal